Update: Waterpik is finally replacing my machine. Amazon apparently contacted them about the poor review I gave. Lesson I learned is that when you need help dealing with a seller ..... call customer service because Amazon is the best at what they do. When my machine "worked" it was fabulous so I have changed my review to 4 stars.
Original Review: It does not work. I called Amazon and Gowri at Amazon was really good .... he said it was best to go through the manufacturer and they will replace it "no problem". Not exactly the way it went. They ignored my explanation of the issue of the battery not holding a charge and just kept sending me letters saying that I needed to do "MORE" troubleshooting. I think they thought maybe I would just "go away". I am not. I want people to know my experience with support from WaterPik. A guy named James just kept sending me emails telling me what I should try. I explained that my wife has the same product and it works fine, so I "DO" know how to work the darn thing. It is simply this ..... I charge the battery overnight then in the morning when I use the machine ...... it stops working before I get to my lower teeth. Like 2 minutes it lasts ..... obviously something is wrong with the batteries. They just kept insisting that I needed to do all these troubleshooting steps ..... I did comply ..... still have not heard whether they were sending me a new replacement yet. I kind of expect they will just keep making me jump through hoops.
I would be willing to update this review, if they perform as expected.
I included a couple pics because they insisted that I needed to give them the serial number. As you can see by the pics ...... there is no serial number on their machine ...... they insisted twice by email to provide that. I suspect they are going to use that as reason to not honor their warranty. Believe me .... blow up that first pic and you will see serial number clearly written, but no number ????? Arghhhhhhhhhh

I bought this as a replacement for a much older version and it's proving to be very helpful. It makes my mouth feel very clean.

Some of the features are such an improvement over my old Waterpik I wish I had purchased it sooner - variable speed, several choices of heads, not too heavy

There's one feature I wish were included: a charging indicator light like many such appliances have. I'm never quite sure if it's fully charged.

It's rather cumbersome for traveling and I gave it three stars for portability because it's clunky for that too, but I have a dedicated charging spot in a bedroom so that's not much of an issue. The pros far outweigh the cons.

Bought this for my own use to replace my warranty-replaced (other brand name here--and that replaced-item failed a second time.) I love that it's cordless. It's probably TMI but having something like this in the shower is amazing. No drooling in the sink and no cleaning up. Plus warm water for my cold-sensitive teeth--GOLD. Compared to my other one, this item has "disappointed me in the following ways" (extra points to you if you get that reference): when I first plugged it in out of the box, it was unclear if it was actually charging or not--no indicator that I could determine--and it doesn't have much pressure behind it even at the higher level. Now, I know, we don't want an over-abundance of pressure, but I do want to feel like it's actually doing something. This feels a little like it's washing gums, etc, rather than cleaning them. It's good enough for now, but could be a little better.

Never had a waterpik before but my dental hygienist recommended it. Couldn't be happier! I hate flossing but look forward to using this. It is so refreshing. I add a little mouthwash for flavor and freshness. Definitely recommend!

This is my second Waterpik after the first one finally died after 12 years of use. Works just as well as that original and even my hygienist is a convert after seeing how good the results are. The only downside to this model is the on/off is a slide switch rather than a push like my previous model. It took a little getting used to but I'm over it now. Also, these are a little bulky and if you travel light, like I do, you might want to revert to old fashioned flossing when away from home.